Etheral  jaunt.The dragon ignored difficult terrain.

semi-etheral form. The dragon has resistance against piercing, slashing and bludgeoning damage.

dual natured. The dragon can use a bonus action to shift into the etheral plane, and use an  bonus action to shift back.

Shadow Born while in dim light and/or darkness the dragon has advantage on stealth checks.

Innate spellcasting:

The dragon’s innate spellcasting ability is Intelligence. It can innately cast the following spells, requiring no material components:

• At will: Friends
• 3/day: enhance ability, Darkness

Multiattack. The dragon makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 15 (2d10 + 4) piercing damage plus 4 (1d8) necrotic damage.

Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) slashing damage.

Dark metallic Breath (Recharge 5–6). The dragon exhales an metalic blast in a 60-foot line. Each creature in that area must make a DC 16 dexterity saving throw, taking 4d6 piercing damage and 4d6 necroic damage. On a succesfull save target takes half damage.